AstrometryConfig#

class lsst.meas.astrom.AstrometryConfig(*args, **kw)#

Bases: RefMatchConfig

Config for AstrometryTask.

Attributes Summary

`cullMagBuffer`	Generous buffer on the fiducial zero point culling to account for observing condition variations and uncertainty of the fiducial values.
`doFiducialZeroPointCull`	If True, use the obs_package-defined fiducial zeropoint values to compute the expected zeropoint for the current exposure.
`doMagnitudeOutlierRejection`	If True then a rough zeropoint will be computed from matched sources and outliers will be rejected in the iterations.
`fiducialZeroPoint`	Fiducial zeropoint values, keyed by band.
`filterMap`	Mapping from physical filter label to reference filter name.
`forceKnownWcs`	If True then load reference objects and match sources but do not fit a WCS; this simply controls whether 'run' calls 'solve' or 'loadAndMatch' (`bool`, default `False`)
`magnitudeOutlierRejectionNSigma`	Number of sigma (measured from the distribution) in magnitude for a potential reference/source match to be rejected during iteration.
`matchDistanceSigma`	the maximum match distance is set to mean_match_distance + matchDistanceSigma*std_dev_match_distance; ignored if not fitting a WCS (`float`, default `2`)
`matcher`	reference object/source matcher (`ConfigurableInstance`, default `<class 'lsst.meas.astrom.matchPessimisticB.MatchPessimisticBConfig'>`)
`maxIter`	maximum number of iterations of match sources and fit WCSignored if not fitting a WCS (`int`, default `3`)
`maxMeanDistanceArcsec`	Maximum mean on-sky distance (in arcsec) between matched source and reference objects post-fit.
`maxRefToSourceRatio`	Maximum ratio of loaded reference objects to detected sources in play.
`minMatchDistanceArcSec`	the match distance below which further iteration is pointless (arcsec); ignored if not fitting a WCS (`float`, default `0.001`)
`refColorDeltaDefaults`	Fallback values for color differences between the reference band and the physical filter of the observation (note that these values apply to LSSTCam filters and may not be appropriate for others).
`referenceSelector`	How to select reference objects for cross-matching.
`sourceFluxType`	Source flux type to use in source selection.
`sourceSelector`	How to select sources for cross-matching.
`wcsFitter`	WCS fitter (`ConfigurableInstance`, default `<class 'lsst.meas.astrom.fitTanSipWcs.FitTanSipWcsConfig'>`)

Methods Summary

`setDefaults`()	Subclass hook for computing defaults.
`validate`()	Validate the Config, raising an exception if invalid.

Attributes Documentation

cullMagBuffer#: Generous buffer on the fiducial zero point culling to account for observing condition variations and uncertainty of the fiducial values. (float, default 0.3)

doFiducialZeroPointCull#: If True, use the obs_package-defined fiducial zeropoint values to compute the expected zeropoint for the current exposure. This is for use in culling reference objects down to the approximate magnitude range of the detection source catalog used for astrometric calibration. (bool, default False)

doMagnitudeOutlierRejection#: If True then a rough zeropoint will be computed from matched sources and outliers will be rejected in the iterations. (bool, default True)

fiducialZeroPoint#: Fiducial zeropoint values, keyed by band. (Dict, default None)

filterMap#: Mapping from physical filter label to reference filter name. (Dict, default {})

forceKnownWcs#: If True then load reference objects and match sources but do not fit a WCS; this simply controls whether ‘run’ calls ‘solve’ or ‘loadAndMatch’ (bool, default False)

magnitudeOutlierRejectionNSigma#: Number of sigma (measured from the distribution) in magnitude for a potential reference/source match to be rejected during iteration. (float, default 3.0)

matchDistanceSigma#

the maximum match distance is set to mean_match_distance + matchDistanceSigma*std_dev_match_distance; ignored if not fitting a WCS (float, default 2)

Valid Range = [0,inf)

matcher#: reference object/source matcher (ConfigurableInstance, default <class 'lsst.meas.astrom.matchPessimisticB.MatchPessimisticBConfig'>)

maxIter#

maximum number of iterations of match sources and fit WCSignored if not fitting a WCS (int, default 3)

Valid Range = [1,inf)

maxMeanDistanceArcsec#

Maximum mean on-sky distance (in arcsec) between matched source and reference objects post-fit. A mean distance greater than this threshold raises BadAstrometryFit and the WCS fit is considered a failure. The default is set to the maximum tolerated by the external global calibration (e.g. jointcal) step for conceivable recovery; the appropriate value will be dataset and workflow dependent. (float, default 0.5)

Valid Range = [0,inf)

maxRefToSourceRatio#: Maximum ratio of loaded reference objects to detected sources in play. If exceded the source catalog will be trimmed to the minimum (i.e. brightest) mag of the reference catalog. (float, default 20.0)

minMatchDistanceArcSec#

the match distance below which further iteration is pointless (arcsec); ignored if not fitting a WCS (float, default 0.001)

Valid Range = [0,inf)

refColorDeltaDefaults#: Fallback values for color differences between the reference band and the physical filter of the observation (note that these values apply to LSSTCam filters and may not be appropriate for others). (Dict, default {'u': -1.5, 'g': -0.6, 'r': 0.0, 'i': 0.5, 'z': 0.6})

referenceSelector#: How to select reference objects for cross-matching. (ConfigurableInstance, default <class 'lsst.meas.algorithms.sourceSelector.ReferenceSourceSelectorConfig'>)

sourceFluxType#: Source flux type to use in source selection. (str, default 'Psf')

sourceSelector#: How to select sources for cross-matching. (RegistryInstanceDict, default 'science')

wcsFitter#: WCS fitter (ConfigurableInstance, default <class 'lsst.meas.astrom.fitTanSipWcs.FitTanSipWcsConfig'>)

Methods Documentation

setDefaults()#: Subclass hook for computing defaults.

Notes#

Derived Config classes that must compute defaults rather than using the Field instances’s defaults should do so here. To correctly use inherited defaults, implementations of setDefaults must call their base class’s setDefaults.

validate()#

Validate the Config, raising an exception if invalid.

Raises#

lsst.pex.config.FieldValidationError: Raised if verification fails.

Notes#

The base class implementation performs type checks on all fields by calling their validate methods.

Complex single-field validation can be defined by deriving new Field types. For convenience, some derived lsst.pex.config.Field-types (ConfigField and ConfigChoiceField) are defined in lsst.pex.config that handle recursing into subconfigs.

Inter-field relationships should only be checked in derived Config classes after calling this method, and base validation is complete.